Congestive heart failure (CHF) is a health problem that affects millions of people in the United States alone. CHF generally includes a loss of cardiac efficiency or cardiac output, and can include an inability to provide sufficient blood flow to meet the metabolic demands of peripheral tissues. CHF patients typically have an enlarged heart with weakened cardiac muscles, resulting in reduced contractility and poor cardiac output.
CHF is usually a chronic condition, but can occur suddenly. It can affect the left heart, right heart, or both sides of the heart. When a left ventricle is affected, for example, signals that control the left ventricular contraction can be delayed, or the left and right ventricles may not contract simultaneously. Non-simultaneous contractions of the left and right ventricles can decrease the pumping efficiency of the heart.